Detailed Analysis of Prebiotic Fructo- and Galacto-Oligosaccharides\nin the Human Small Intestine

Galacto-oligosaccharides\n(GOS) and fructo-oligosaccharides (FOS)\nare food ingredients that improve human health, but their degradation\nthroughout the human small intestine is not well understood. We studied\nthe breakdown kinetics of FOS and GOS in the intestines of seven healthy\nDutch adults. Subjects were equipped with a catheter in the distal\nileum or proximal colon and consumed 5 g of chicory-derived FOS (degree\nof polymerization (DP) DP2–10), and 5 g of GOS (DP2–6).\nPostprandially, intestinal content was frequently collected until\n350 min and analyzed for mono-, di-, and oligosaccharides. FOS and\nGOS had recoveries of 96 ± 25% and 76 ± 28%, respectively.\nFOS DP ≥ 2 and GOS DP ≥ 3 abundances in the distal small\nintestine or proximal colon matched the consumed doses, while GOS\ndimers (DP2) had lower recoveries, namely 22.8 ± 11.1% for β-D-gal-(1↔1)-α-D-glc+β-D-gal-(1↔1)-β-D-glc,\n19.3 ± 19.1% for β-D-gal-(1 → 2)-D-glc+β-D-gal-(1\n→ 3)-D-glc, 43.7 ± 24.6% for β-D-gal-(1 →\n6)-D-gal, and 68.0 ± 38.5% for β-D-gal-(1 → 4)-D-gal.\nLactose was still present in the distal small intestine of all of\nthe participants. To conclude, FOS DP ≥ 2 and GOS DP ≥\n3 were not degraded in the small intestine of healthy adults, while\nmost prebiotic GOS DP2 was hydrolyzed in a structure-dependent manner.\nWe provide evidence on the resistances of GOS with specific β-linkages\nin the human intestine, supporting the development of GOS prebiotics\nthat resist small intestine digestion.